Poyntonophrynus beiranus (Loveridge, 1932)
Original Published Description:
Beira's Toad (English), Beira Toad (English), Beira Pygmy Toad (English)
Poyntonophrynus beiranus is found in two distinct and disjoint ecoregions: the Zambezian flooded grasslands and the Zambezian coastal flooded savanna; elevation of occurrence is less than 1000 meters above sea level. Breeding is thought to occur in emphemeral pools formed in lowland floodplains subsequent to intermittent heavy rains. The conservation status is classified as Least Concern, even though there is little data to support population estimates or trend.
P. beiranus has a disjunctive distribution, occurring in at least two quite distinct areas: (1) the coastal plain of central Mozambique within the floodplain of the Pungwe River (alternatively known as the Pungwe Flats), northward to Thuchila in southern Malawi; and (2) floodplains in the Middle Zambezi River catchment area in central and southwestern Zambia. The species is under-recorded, and probably occurs more broadly than the officially reported range, especially between the two noted disjunctive areas. Elevation of occurrence is between sea level and at least 1000 meters above mean sea level (Tandy et al. 2004).
With regard to the westernmost population element, the extent is at least as far as the Barotse floodplains.
The ventrum is pale or manifests minute black spots that do not fuse together. There is also a range diagnostic that differentiates the Beira Pygmy Toad from any other Pygmy Toads: that the Beira Toad is found only in low lying parts of eastern Mozambique or Middle Zambezi drainage of south central Zambia (Du Preez et al. 2009).
Like all of its genus members, P. beiranus has parotoid glands which are not prominent and do not form a continuous platform with the top of the head. As a genus diagnostic this toad lacks any dorsal hourglass patternation, and no conspicuous tarsal fold. Again, as with all genus members the ventral skin is granular. The inner metatarsal is inconspicuous and not flanged for burrowing. There are no adhesive terminal discs on either the fingers or toes. There are no hard claws and eye pupils are never vertical (Du Preez et al. 2009).
Habitat and Ecology
The species natural habitats consist of subtropical or tropical dry shrubland; subtropical or tropical seasonally wet or flooded lowland grasslands; and intermittent freshwater marshes. P. beiranus is found in two distinct and disjoint ecoregions: the Zambezian flooded grasslands (World Wildlife Fund & Hogan, 2007) and the Zambezian coastal flooded savanna. The warmest part of the range is in the Zambezian coastal flooded savanna, where the warmest month is February with a mean maximum temperature of 81.7 degrees Fahrenheit over the 109 period of record. Frost events are infrequent, and may occur several days per year.
Further field research is needed to identify the species preferred habitat; to date, most observations have been made in grassland areas that flood intermittently subsequent to rains. Its adaptability to human altered habitats is not well known.
As of the year 2004 the IUCN has asserted that the population status of P. beiranus is unknown (Tandy et al. 2004).
A number of amphibian associates are found within the ecoregions where P. beiranus occurs, including: African clawed toad (Xenopus laevis), African ornate frog (Hildebrandtia ornata), Boettger’s metal frog (Cacosternum boettgeri), Common reed frog (Hyperolius viridiflavus), and the Lukula grass frog (Ptychadena taenioscellus; World Wildlife Fund & Hogan, 2007).
Many of the ungulates that inhabit these ecoregions move seasonally through the floodplain in response to the fluctuating water levels. Topi (Damaliscus lunatus), which are mostly restricted to seasonally flooded grasslands, are known to follow the receding waters in the dry season and to retreat to higher ground after peak rain events. Blue Wildebeest (Connochaetes taurinus) and Oribi (Ourebia ourebi) also frequent the extensive floodplains and grasslands, although the latter favor less waterlogged areas such as termitaries, where herbs and woody growth provide food and cover. Waterbuck (Kobus ellipsiprymnus), Puku (Kobus vardoni), Southern reedbuck (Redunca arundinum), and sitatunga (Tragelaphus spekei) are also common inhabitants of the floodplains in the range of P. beiranus (World Wildlife Fund & Hogan, 2007).
Zambian barbet (Lybius chaplini) is endemic to south central Zambia, concentrated in the Kafue basin between Kafue National Park and Lusaka. Reliant on miombo woodland or open country bearing fruiting trees, this species is mostly found on the woody margins of flooded grassland areas. Other globally threatened species recorded in portions of the range of P. beiranus include Wattled crane (Grus carunculatus,VU), which has its main breeding populations in the wetlands of Zambia, including the Kafue Flats and the Bangweulu and Busanga swamps, Corncrake (Crex crex, VU), Lesser kestrel (Falco naumanni, VU), Great snipe (Gallinago media) and Shoebill stork (Balaeniceps rex; World Wildlife Fund & Hogan, 2007).
Little is known regarding the species breeding behavior, though reproduction is thought to occur in emphemeral pools formed subsequent to intermittent heavy rains (Tandy et al. 2004).
The advertisement call is a high frequency insect-like buzz (Du Preez et al. 2009).
IUCN Red List Category and Justification of Conservation Status
P. beiranus has been listed by the IUCN as Least Concern because, although infrequently recorded, the taxon has a relatively wide distribution, and occurs in a region with extensive available habitats; furthermore, this anuran has a presumed large population, and is thought by the IUCN unlikely to be declining rapidly enough to qualify for listing in a more threatened category (Tandy et al. 2004).
Chief threats to the species are driven by the expanding human population of the region, and are common to the ecoregion threats. Prime factors related to all amphibians in the range are: over-extraction of surface waters, conversion of land to agriculture, deforestation of swamp forests, overgrazing and fragmentation of habitat. (World Wildlife Fund & Hogan, 2007).
Conservation Actions and Management
P. beiranus likely occurs within several protected areas, notably the Kafue National Park (Tandy et al. 2004) and South Luangwa National Park of Zambia.
- Bufo taitanus beiranus Loveridge, 1932 (synonym)
- Bufo beiranus Grandison, 1972 (synonym)
- Poyntonophrynus beiranus Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, 2006 (synonym)